Orris root

from The Collaborative International Dictionary of English v.0.48

Orris \Or"ris\, n. [Prob. corrupted from It. ireos iris. See
   {Iris}.] (Bot.)
   A plant of the genus {Iris} ({Iris Florentina}); a kind of
   flower-de-luce. Its rootstock has an odor resembling that of
   violets.
   [1913 Webster]

   {Orris pea} (Med.), an issue pea made from orris root.

   {Orris root}, the fragrant rootstock of the orris.
      [1913 Webster]